import optparse
import socket
from socket import *
from threading import *

screenLock = Semaphore(value=1)

def connScan(tgtHost,tgtPort):
    try:
        connSkt = socket(AF_INET,SOCK_STREAM)
        connSkt.connect((tgtHost,tgtPort))
        connSkt.send('ViolentPython\r\n'.encode('utf-8'))
        result = connSkt.recv(1024)
        screenLock.acquire()
        print("[+] %d/tcp open"%tgtPort)
        print("[+]"+str(result))
    except Exception as e:
        screenLock.acquire()
        print(e)
    finally:
        screenLock.release()
        connSkt.close()


def portScan(tgtHost,tgtPorts):
    try:
        tgtIp = gethostbyname(tgtHost)
    except:
        print("[-] Cannot reslove '%s' : Unknown host" % tgtHost)
        return

    try:
        tgtName = gethostbyaddr(tgtIp)
        print("\n [+] Scan Result for: " + tgtName[0])
    except:
        print("\n [+] Scan Result for: " + tgtIp)

    setdefaulttimeout(1)
    for tgtPort in tgtPorts:
        print("Scanning port "+ tgtPort)
        t = Thread(target=connScan,args=(tgtHost,int(tgtPort)))
        t.start()

def main():
    parser = optparse.OptionParser("usage%prog -H <target host> -p <target port>")
    parser.add_option('-H',dest='tgtHost',type='string',help='specify target host')
    parser.add_option('-p',dest='tgtPort',type='string',help='specify target port[s] separated by comma')
    options,args = parser.parse_args()
    tgtHost = options.tgtHost
    tgtPorts = str(options.tgtPort).split(',')
    if(tgtHost == None or tgtPorts[0] == None):
        print("[-] You must specify a target host and port[s]")
        exit(0)
    portScan(tgtHost,tgtPorts)

if __name__ == '__main__':
    main()
